I think the ps3 is about as powerful as we've all been lead to believe. It was originally designed to play 2d 1080p games. In order to do 3d it pretty much had do to twice the work (so it came play two frames simutaneously). The ps3 is a number of years old, and wasn't designed at all. Its almost like playing two video games at once.
I'm sure the nextgen, taking advantage of more modern hardware will have an easier time with it. The ps3/360 were never really designed to have the firepower to do 3d, as 3d wasn't really talked about when the came out.